1. Field of the Invention
Modern internal combustion engine design is undergoing important changes to meet stricter standards concerning engine and exhaust gas emissions. One major change in engine design adopted is the feeding of blow-by gases from the crankcase zone of the engine into the intake air-fuel mixture at the carburetor just below the throttle plate rather than venting these gases to the atmosphere as in the past. The blow-by gases contain substantial amounts of deposit-forming substances and are known to form deposits in and around the throttle plate area of the carburetor. Another significant change is the recirculation of a part of the exhaust gases to the fuel-air intake of the engine. The exhaust gases also have deposit-forming tendencies. The deposits caused by the recirculated gases, both blow-by and exhaust gases, restrict the flow of air through the carburetor at idle and at low speeds, and an overrich fuel mixture results. This condition produces rough engine idling and stalling and leads to the release of excessive hydrocarbon exhaust emissions to the atmosphere.
Phosphorus compounds have heretofore been disclosed for use in a motor fuel composition both as deposit modifiers to inhibit preignition in the engine and as surface active agents to reduce carburetor icing problems. As a result of recent environmental developments, regulations have been promulgated directed to the level of phosphorus which can be present in a motor fuel composition. The Environmental Protection Agency has issued a standard for such a fuel which specifies that "unleaded gasoline" and, by implication, a phosphorus-free gasoline "means gasoline containing not more than 0.05 gram of lead per gallon and not more than 0.005 gram of phosphorus per gallon." Many of the known phosphorus fuel additives are ineffective for their intended purpose in gasoline at such a low concentration.
Telomeric phosphorus compounds are obtained in a reaction wherein an olefin is telomerized in the presence of a phosphorus containing free radical until a plurality of olefin monomers have been so reacted. As indicated, the reaction resembles polymerization in that olefin monomers can be continuously fed to the reaction until a telomeric phosphorus compound of desired properties has been obtained at which time the reaction is stopped.